The present invention relates to a blade of an electric shaver, method of shaving, and an electric shaver.
Generally, a blade of an electric shaver is provided with an exterior blade formed in a sheet-shape having a plurality of apertures, and an interior blade which slides on the bottom surface of the exterior blade relative to the exterior blade. FIG. 16 shows how a human beard (31) is shaved by using a conventional blade of an electric shaver. According to the conventional blade of an electric shaver shown in FIG. 16, a sharp edge (40) is formed at a top side end of an interior blade (3). Upon pressing the human skin (30) having the beard (31) by the electric shaver, the skin (30) protrudes beyond the exterior blade (2) through the apertures (1). Under this condition, as the interior blade (3) is moved along the surface of the skin (30), the beard (31) is introduced into the aperture (1) and is cut by the sharp edge (40) of the interior blade (3). According to the above described conventional blade of an electric shaver illustrated in FIG. 16, however, there is a drawback in that the skin (30) may be damaged by excess stimulations because the surface of the skin (30) is shaved by the interior blade (3). Also, in order for the interior blade (3) to have the sharp edge (40), the interior blade (3) needs to be precisely processed. Further, there is a risk of injury at the time of cleaning of the interior blade (3).
A conventional blade of an electric shaver disclosed by Japanese patent laid open JITSUKAIHEI 54-113692 is illustrated in FIGS. 17-19. According to this conventional blade, a plurality of convexities (50) which do not have a cutting edge (41) are partially formed along the top end of the interior blade (3). By providing such convexities (50) as a guard at the top end of the interior blade (3), damages to the skin (30) can be prevented. Under this configuration, the size of the apertures (1) of the exterior blade (2) can be set such that the beard (31) can be efficiently introduced into the apertures (1).
However, according to the above described conventional blade of an electric shaver, because sharp cutting edges (41) must be formed at the interior blade (3), damages to the skin (30) cannot be prevented except for the areas where the convexities (50) are formed. As a result, the size of the apertures (1) of the exterior blade (2) is inevitably restricted to prevent such damages. Also, if the blade (3) is formed such that only the convexities (50) contact the skin (30) and the cutting edge (41) does not directly contact the skin (30), the area of the convexities (50) becomes enlarged and the gap between the exterior blade (2) and the cutting edge (41) of the interior blade (3) becomes large. As a result, cutting performance of the blade becomes deteriorated. What is needed is, therefore, a blade of an electric shaver having good cutting performance without damaging the skin.
In general, in one aspect, the present invention is a blade of an electric shaver. The blade comprises an interior blade detachably attached to a drive element of the electric shaver via an interior blade pushing-up means. The interior blade comprises a horizontal surface, a vertical surface, and a relief surface provided between the horizontal surface and the vertical surface, and is elastically pushed upward by the interior blade pushing-up means. The blade further comprises a sheet-shaped exterior blade having a plurality of blade apertures. A bottom surface of the exterior blade is elastically contacted with the horizontal surface of the interior blade by a pushing force of the interior blade pushing-up means. Upon driving the drive element, the interior blade is moved laterally such that the horizontal surface of the interior blade rubs against the bottom surface of the exterior blade, and hair introduced into the blade aperture of the exterior blade is held between the horizontal surface of the interior blade and the exterior blade in accordance with a lateral movement of the interior blade and cut by an edge of the exterior blade.
In general, in one aspect, the present invention is a method for shaving hair by using a blade of an electric shaver. The blade used in this method comprises an interior blade and a sheet-shaped exterior blade. The interior blade is detachably attached to a drive element of the electric shaver via an interior blade pushing-up means and comprises a horizontal surface, a vertical surface, and a relief surface formed between the horizontal surface and the vertical surface. The exterior blade comprises a plurality of blade apertures. A bottom surface of the exterior blade is elastically contacted with the horizontal surface of the interior blade by a pushing force of the interior blade pushing-up means. By driving the drive element such that the horizontal surface of the interior blade is moved laterally to rub the bottom surface of the exterior blade, and contacting an outer surface of the exterior blade with hair such that the hair is introduced into a blade aperture of the exterior blade, the hair thus introduced into the blade aperture is held between the interior blade and the exterior blade in accordance with a lateral movement of the interior blade and cut by an edge of the exterior blade.
In general, in one aspect, the present invention is an electric shaver. The electric shaver comprises a main body having a motor therein, a frame member disposed on a top of the main body, a drive element projecting upward from an upper surface of the frame member and driven by the motor, an interior blade detachably attached to the drive element via an interior blade pushing-up means, the interior blade having a horizontal surface, a vertical surface, and a relief surface provided between the horizontal surface and the vertical surface, and elastically pushed upward by the interior blade pushing-up means, and a head attached to the frame member to cover the interior blade, the head comprising a sheet-shaped exterior blade having a plurality of blade apertures attached to the head, the bottom surface of the exterior blade elastically contacting with the horizontal surface of the interior blade. Upon driving the drive element, the interior element moves laterally such that the horizontal surface of the interior blade rubs against the bottom surface of the exterior blade, and hair introduced into the blade aperture of the exterior blade is held between the horizontal surface of the interior blade and the exterior blade in accordance with a lateral movement of the interior blade and cut by an edge of the exterior blade.